public class Example4_7{
   public static void main (String args[]){
      Battery nanfu = new Battery(100);
      System.out.println("南浮电池的储电量是 :"+nanfu.electricityAmount);
      Radio radio = new Radio();
      System.out.println(" 收音机开始使用南浮电池");
      radio.openRadio(nanfu);
      System.out.println("目前南浮电池的储电量是 :"+nanfu.electricityAmount);
   }
}
